Sandstones are, as a rule , interbedded with shales.
砂岩通常都与页岩互层.
This paper presents the PDC bits with the satisfactory testing result in the multi - interbedded formation.
介绍了一种复合式PDC钻头,该钻头在多夹层地层钻井施工中取得了较好的试验效果.
The characteristics of the Suhongtu Formation reflect shore - shallow and semi - deep lake sediments interbedded with volcanogenic rock.
其中,苏红图组沉积时期伴随火山的活动,呈现滨浅湖、半深湖沉积与区域性火山岩相间的分布特征.